WASHINGTON — There is no evidence that White House officials were involved in withholding information related to a congressional inquiry into the botched gun-trafficking operation known as "Fast and Furious," the Republican lawmaker leading the investigation said Sunday.

Several Republican lawmakers, including House Speaker John Boehner, R-Ohio, charged last week that President Barack Obama's decision to invoke executive privilege over documents related to the inquiry suggested top officials were involved in withholding information.

"The decision to invoke executive privilege is an admission that White House officials were involved in a decision that misled the Congress and have covered up the truth," Boehner told reporters last week.

But asked Sunday whether he had any evidence to back up those claims, Rep. Darrell Issa, R-Calif., said: "No, we don't."

"What we're seeking are documents that we know exist … that are, in fact, about Brian Terry's murder, who knew and why people were lying about it and get to the truth. That's all we want," Issa said on Fox News Sunday.

Terry, a U.S. Border Patrol agent, was killed in December 2010 and investigators later found two guns connected to Fast and Furious, an operation named after the popular movie series that was run out of the Phoenix division of the Bureau of Alcohol, Tobacco, Firearms and Explosives between 2009 and 2011, with support from the U.S. attorney in Phoenix.

As part of the operation, ATF agents purposefully did not seize more than 2,000 weapons they suspected of being purchased at Arizona gun shops by illegal buyers known as "straw purchasers."

Issa, chairman of the House Oversight and Government Reform Committee, has led a roughly 18-month investigation into the operation that includes dozens of interviews with Justice Department and ATF officials and public hearings, including several appearances by Attorney General Eric Holder.

But Issa's committee last week voted to recommend that Holder be held in contempt for withholding information. Boehner and House GOP leaders plan to hold a vote this week in the full House on the recommendations.